Couldn't find it, so I recalculated it:
If I share The Gospel with two people today, and each of them shares The Gospel with two people tomorrow, and each of them share The Gospel with two people the next day, and so on, sometime on Day 33, every person on the planet will have received The Gospel. Assuming no duplicates, and assuming no one shared The Gospel with more than two people, and assuming everyone did his or her part by sharing The Gospel with two people the day after he or she received The Gospel.
Day 1: 1 person shares The Gospel with 2 people = 2 heard + 1 = 3 total reached with The Gospel
Day 2: 2 people share The Gospel with 2 people each = 4 heard + 3 = 7 total reached with The Gospel
Day 3: 4 people share The Gospel with 2 people each = 8 heard + 7 = 15 total reached with The Gospel
Day 4: 8 people share The Gospel with 2 people each = 16 heard + 15 = 31 total reached with The Gospel
Day 5: 16 x 2 = 32 + 31 = 63 total reached with The Gospel
Day 6: 32 x 2 = 64 + 63 = 127
Day 7: 64 x 2 = 128
Day 8: 128 x 2 = 256
Day 9: 256 x 2 = 512
Day 10: 512 x 2 = 1024
Day 11: 1024 x 2 = 2048
Day 12: 2048 x 2 = 4096
Day 13: 4096 x 2 = 8192
Day 14: 8192 x 2 = 16,384
Day 15: 16,384 x 2 = 32,768
Day 16: 32,768 x 2 = 65,536
Day 17: 65,536 x 2 = 131,072
Day 18: 131,072 x 2 = 262,144
Day 19: 262,144 x 2 = 524,288
Day 20: 524,288 x 2 = 1,048,576
Day 21: 1,048,576 x 2 = 2,097,152
Day 22: 2,097,152 x 2 = 4,194,304
Day 23: 4,194,304 x 2 = 8,388,608
Day 24: 8,388,608 x 2 = 16,777,216
Day 25: 16,777,216 x 2 = 33,554,432
Day 26: 33,554,432 x 2 = 67,108,864
Day 27: 67,108,864 x 2 = 134,217,218
Day 28: 134,217,218 x 2 = 268,435,456
Day 29: 268,435,456 x 2 = 536,870,912
Day 30: 536,870,912 x 2 = 1,073,741,824
Day 31: 1,073,741,824 x 2 = 2,147,438,648
Day 32: 2,147,438,648 x 2 = 4,294,967,296 + 2,147,438,647 = 6,442,405,943 total reached with The Gospel
Day 33: 4,294,967,296 x 2 = 8,589,934,592 + 4,294,967,295 = 12,884,901,887 total reached with The Gospel
According to World Population Review
https://worldpopulationreview.com/countries/deaths-per-day
The current world population is approximately 8.1 billion, there are approximately 269,859 deaths each day, and there are approximately 368,144 births per day.
269,859 x 33 = 8,905,347 deaths in 33 days
368,144 x 33 = 12,148,752 births in 33 days
8,905,347 + 12,148,752 = 21,054,099 population turnover in 33 days
8,100,000,000 estimated population + 21,054,099 approximate turnover = 8,121,054,099 approximate total number of people on the planet, including turnover, during a 33 day period in 2024.
So, using this model, assuming everything went according to plan, sometime on Day 33, everyone on the planet could and would be reached with The Gospel
Imagine how much faster this would go if everyone, who was reached, kept on sharing The Gospel with two more people every day, starting more chains
Dear God . . . PLEASE!!!